package cn.com.dhc.danlu.util;

/**
 * Copyright (c) 2012-2013, Michael Yang 杨福海 (www.yangfuhai.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.PixelFormat;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;

import org.json.JSONArray;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.RandomAccessFile;
import java.io.Serializable;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;

/**
 * @author Michael Yang（www.yangfuhai.com） update at 2013.08.07
 */
public class ACache {
    public static final int TIME_HOUR = 60 * 60;
    public static final int TIME_DAY = TIME_HOUR * 24;
    private static final int MAX_SIZE = 1000 * 1000 * 50; // 50 mb
    private static final int MAX_COUNT = Integer.MAX_VALUE; // 不限制存放数据的数量
    private static Map<String, ACache> mInstanceMap = new HashMap<> ();
    private ACacheManager mCache;

    private ACache (File cacheDir, long max_size, int max_count) {
        if (!cacheDir.exists () && !cacheDir.mkdirs ()) {
            throw new RuntimeException ("can't make dirs in " + cacheDir.getAbsolutePath ());
        }
        mCache = new ACacheManager (cacheDir, max_size, max_count);
    }

    public static ACache get (Context ctx) {
        return get (ctx, "ACache");
    }

    public static ACache get (Context ctx, String cacheName) {
        File f = new File (ctx.getCacheDir (), cacheName);
        return get (f, MAX_SIZE, MAX_COUNT);
    }

    public static ACache get (File cacheDir) {
        return get (cacheDir, MAX_SIZE, MAX_COUNT);
    }

    public static ACache get (Context ctx, long max_zise, int max_count) {
        File f = new File (ctx.getCacheDir (), "ACache");
        return get (f, max_zise, max_count);
    }

    public static ACache get (File cacheDir, long max_zise, int max_count) {
        ACache manager = mInstanceMap.get (cacheDir.getAbsoluteFile () + myPid ());
        if (manager == null) {
            manager = new ACache (cacheDir, max_zise, max_count);
            mInstanceMap.put (cacheDir.getAbsolutePath () + myPid (), manager);
        }
        return manager;
    }

    private static String myPid () {
        return "_" + android.os.Process.myPid ();
    }

    /**
     * 保存 String数据 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的String数据
     */
    public void put (String key, String value) {
        File file = mCache.newFile (key);
        BufferedWriter out = null;
        try {
            out = new BufferedWriter (new FileWriter (file), 1024);
            out.write (value);
        } catch (IOException e) {
            e.printStackTrace ();
        } finally {
            if (out != null) {
                try {
                    out.flush ();
                    out.close ();
                } catch (IOException e) {
                    e.printStackTrace ();
                }
            }
            mCache.put (file);
        }
    }

    // =======================================
    // ============ String数据 读写 ==============
    // =======================================

    /**
     * 保存 String数据 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的String数据
     * @param saveTime
     *         保存的时间，单位：秒
     */
    public void put (String key, String value, int saveTime) {
        put (key, Utils.newStringWithDateInfo (saveTime, value));
    }

    /**
     * 读取 String数据
     *
     * @return String 数据
     */
    public String getAsString (String key) {
        File file = mCache.get (key);
        if (!file.exists ()) {
            return null;
        }
        boolean removeFile = false;
        BufferedReader in = null;
        try {
            in = new BufferedReader (new FileReader (file));
            String readString = "";
            String currentLine;
            while ((currentLine = in.readLine ()) != null) {
                readString += currentLine;
            }
            if (!Utils.isDue (readString)) {
                return Utils.clearDateInfo (readString);
            } else {
                removeFile = true;
                return null;
            }
        } catch (IOException e) {
            e.printStackTrace ();
            return null;
        } finally {
            if (in != null) {
                try {
                    in.close ();
                } catch (IOException e) {
                    e.printStackTrace ();
                }
            }
            if (removeFile) {
                remove (key);
            }
        }
    }

    /**
     * 保存 JSONObject数据 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的JSON数据
     */
    public void put (String key, JSONObject value) {
        put (key, value.toString ());
    }

    // =======================================
    // ============= JSONObject 数据 读写 ==============
    // =======================================

    /**
     * 保存 JSONObject数据 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的JSONObject数据
     * @param saveTime
     *         保存的时间，单位：秒
     */
    public void put (String key, JSONObject value, int saveTime) {
        put (key, value.toString (), saveTime);
    }

    /**
     * 读取JSONObject数据
     *
     * @return JSONObject数据
     */
    public JSONObject getAsJSONObject (String key) {
        String JSONString = getAsString (key);
        try {
            return new JSONObject (JSONString);
        } catch (Exception e) {
            e.printStackTrace ();
            return null;
        }
    }

    /**
     * 保存 JSONArray数据 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的JSONArray数据
     */
    public void put (String key, JSONArray value) {
        put (key, value.toString ());
    }

    // =======================================
    // ============ JSONArray 数据 读写 =============
    // =======================================

    /**
     * 保存 JSONArray数据 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的JSONArray数据
     * @param saveTime
     *         保存的时间，单位：秒
     */
    public void put (String key, JSONArray value, int saveTime) {
        put (key, value.toString (), saveTime);
    }

    /**
     * 读取JSONArray数据
     *
     * @return JSONArray数据
     */
    public JSONArray getAsJSONArray (String key) {
        String JSONString = getAsString (key);
        try {
            return new JSONArray (JSONString);
        } catch (Exception e) {
            e.printStackTrace ();
            return null;
        }
    }

    /**
     * 保存 byte数据 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的数据
     */
    public void put (String key, byte[] value) {
        File file = mCache.newFile (key);
        FileOutputStream out = null;
        try {
            out = new FileOutputStream (file);
            out.write (value);
        } catch (Exception e) {
            e.printStackTrace ();
        } finally {
            if (out != null) {
                try {
                    out.flush ();
                    out.close ();
                } catch (IOException e) {
                    e.printStackTrace ();
                }
            }
            mCache.put (file);
        }
    }

    // =======================================
    // ============== byte 数据 读写 =============
    // =======================================

    /**
     * Cache for a stream
     *
     * @param key
     *         the file name.
     * @return OutputStream stream for writing data.
     * @throws FileNotFoundException
     *         if the file can not be created.
     */
    public OutputStream put (String key) throws FileNotFoundException {
        return new xFileOutputStream (mCache.newFile (key));
    }

    /**
     * @param key
     *         the file name.
     * @return (InputStream or null) stream previously saved in cache.
     * @throws FileNotFoundException
     *         if the file can not be opened
     */
    public InputStream get (String key) throws FileNotFoundException {
        File file = mCache.get (key);
        if (!file.exists ()) {
            return null;
        }
        return new FileInputStream (file);
    }

    /**
     * 保存 byte数据 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的数据
     * @param saveTime
     *         保存的时间，单位：秒
     */
    public void put (String key, byte[] value, int saveTime) {
        put (key, Utils.newByteArrayWithDateInfo (saveTime, value));
    }

    /**
     * 获取 byte 数据
     *
     * @return byte 数据
     */
    public byte[] getAsBinary (String key) {
        RandomAccessFile RAFile = null;
        boolean removeFile = false;
        try {
            File file = mCache.get (key);
            if (!file.exists ()) {
                return null;
            }
            RAFile = new RandomAccessFile (file, "r");
            byte[] byteArray = new byte[(int) RAFile.length ()];
            RAFile.read (byteArray);
            if (!Utils.isDue (byteArray)) {
                return Utils.clearDateInfo (byteArray);
            } else {
                removeFile = true;
                return null;
            }
        } catch (Exception e) {
            e.printStackTrace ();
            return null;
        } finally {
            if (RAFile != null) {
                try {
                    RAFile.close ();
                } catch (IOException e) {
                    e.printStackTrace ();
                }
            }
            if (removeFile) {
                remove (key);
            }
        }
    }

    /**
     * 保存 Serializable数据 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的value
     */
    public void put (String key, Serializable value) {
        put (key, value, -1);
    }

    // =======================================
    // ============= 序列化 数据 读写 ===============
    // =======================================

    /**
     * 保存 Serializable数据到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的value
     * @param saveTime
     *         保存的时间，单位：秒
     */
    public void put (String key, Serializable value, int saveTime) {
        ByteArrayOutputStream baos;
        ObjectOutputStream oos = null;
        try {
            baos = new ByteArrayOutputStream ();
            oos = new ObjectOutputStream (baos);
            oos.writeObject (value);
            byte[] data = baos.toByteArray ();
            if (saveTime != -1) {
                put (key, data, saveTime);
            } else {
                put (key, data);
            }
        } catch (Exception e) {
            e.printStackTrace ();
        } finally {
            try {
                oos.close ();
            } catch (IOException ignored) {
            }
        }
    }

    /**
     * 读取 Serializable数据
     *
     * @return Serializable 数据
     */
    public Object getAsObject (String key) {
        byte[] data = getAsBinary (key);
        if (data != null) {
            ByteArrayInputStream bais = null;
            ObjectInputStream ois = null;
            try {
                bais = new ByteArrayInputStream (data);
                ois = new ObjectInputStream (bais);
                return ois.readObject ();
            } catch (Exception e) {
                e.printStackTrace ();
                return null;
            } finally {
                try {
                    if (bais != null) {
                        bais.close ();
                    }
                } catch (IOException e) {
                    e.printStackTrace ();
                }
                try {
                    if (ois != null) {
                        ois.close ();
                    }
                } catch (IOException e) {
                    e.printStackTrace ();
                }
            }
        }
        return null;

    }

    /**
     * 保存 bitmap 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的bitmap数据
     */
    public void put (String key, Bitmap value) {
        put (key, Utils.Bitmap2Bytes (value));
    }

    // =======================================
    // ============== bitmap 数据 读写 =============
    // =======================================

    /**
     * 保存 bitmap 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的 bitmap 数据
     * @param saveTime
     *         保存的时间，单位：秒
     */
    public void put (String key, Bitmap value, int saveTime) {
        put (key, Utils.Bitmap2Bytes (value), saveTime);
    }

    /**
     * 读取 bitmap 数据
     *
     * @return bitmap 数据
     */
    public Bitmap getAsBitmap (String key) {
        if (getAsBinary (key) == null) {
            return null;
        }
        return Utils.Bytes2Bimap (getAsBinary (key));
    }

    /**
     * 保存 drawable 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的drawable数据
     */
    public void put (String key, Drawable value) {
        put (key, Utils.drawable2Bitmap (value));
    }

    // =======================================
    // ============= drawable 数据 读写 =============
    // =======================================

    /**
     * 保存 drawable 到 缓存中
     *
     * @param key
     *         保存的key
     * @param value
     *         保存的 drawable 数据
     * @param saveTime
     *         保存的时间，单位：秒
     */
    public void put (String key, Drawable value, int saveTime) {
        put (key, Utils.drawable2Bitmap (value), saveTime);
    }

    /**
     * 读取 Drawable 数据
     *
     * @return Drawable 数据
     */
    public Drawable getAsDrawable (String key) {
        if (getAsBinary (key) == null) {
            return null;
        }
        return Utils.bitmap2Drawable (Utils.Bytes2Bimap (getAsBinary (key)));
    }

    /**
     * 获取缓存文件
     *
     * @return value 缓存的文件
     */
    public File file (String key) {
        File f = mCache.newFile (key);
        if (f.exists ()) {
            return f;
        }
        return null;
    }

    /**
     * 移除某个key
     *
     * @return 是否移除成功
     */
    public boolean remove (String key) {
        return mCache.remove (key);
    }

    /**
     * 清除所有数据
     */
    public void clear () {
        mCache.clear ();
    }

    /**
     * @author 杨福海（michael） www.yangfuhai.com
     * @version 1.0
     */
    private static class Utils {

        private static final char mSeparator = ' ';

        /**
         * 判断缓存的String数据是否到期
         *
         * @return true：到期了 false：还没有到期
         */
        private static boolean isDue (String str) {
            return isDue (str.getBytes ());
        }

        /**
         * 判断缓存的byte数据是否到期
         *
         * @return true：到期了 false：还没有到期
         */
        private static boolean isDue (byte[] data) {
            String[] strs = getDateInfoFromDate (data);
            if (strs != null && strs.length == 2) {
                String saveTimeStr = strs[0];
                while (saveTimeStr.startsWith ("0")) {
                    saveTimeStr = saveTimeStr.substring (1, saveTimeStr.length ());
                }
                long saveTime = Long.valueOf (saveTimeStr);
                long deleteAfter = Long.valueOf (strs[1]);
                if (System.currentTimeMillis () > saveTime + deleteAfter * 1000) {
                    return true;
                }
            }
            return false;
        }

        private static String newStringWithDateInfo (int second, String strInfo) {
            return createDateInfo (second) + strInfo;
        }

        private static byte[] newByteArrayWithDateInfo (int second, byte[] data2) {
            byte[] data1 = createDateInfo (second).getBytes ();
            byte[] retdata = new byte[data1.length + data2.length];
            System.arraycopy (data1, 0, retdata, 0, data1.length);
            System.arraycopy (data2, 0, retdata, data1.length, data2.length);
            return retdata;
        }

        private static String clearDateInfo (String strInfo) {
            if (strInfo != null && hasDateInfo (strInfo.getBytes ())) {
                strInfo = strInfo.substring (strInfo.indexOf (mSeparator) + 1, strInfo.length ());
            }
            return strInfo;
        }

        private static byte[] clearDateInfo (byte[] data) {
            if (hasDateInfo (data)) {
                return copyOfRange (data, indexOf (data, mSeparator) + 1, data.length);
            }
            return data;
        }

        private static boolean hasDateInfo (byte[] data) {
            return data != null && data.length > 15 && data[13] == '-' && indexOf (data, mSeparator) > 14;
        }

        private static String[] getDateInfoFromDate (byte[] data) {
            if (hasDateInfo (data)) {
                String saveDate = new String (copyOfRange (data, 0, 13));
                String deleteAfter = new String (copyOfRange (data, 14, indexOf (data, mSeparator)));
                return new String[] {saveDate, deleteAfter};
            }
            return null;
        }

        private static int indexOf (byte[] data, char c) {
            for (int i = 0; i < data.length; i++) {
                if (data[i] == c) {
                    return i;
                }
            }
            return -1;
        }

        private static byte[] copyOfRange (byte[] original, int from, int to) {
            int newLength = to - from;
            if (newLength < 0) {
                throw new IllegalArgumentException (from + " > " + to);
            }
            byte[] copy = new byte[newLength];
            System.arraycopy (original, from, copy, 0, Math.min (original.length - from, newLength));
            return copy;
        }

        private static String createDateInfo (int second) {
            String currentTime = System.currentTimeMillis () + "";
            while (currentTime.length () < 13) {
                currentTime = "0" + currentTime;
            }
            return currentTime + "-" + second + mSeparator;
        }

        /*
         * Bitmap → byte[]
         */
        private static byte[] Bitmap2Bytes (Bitmap bm) {
            if (bm == null) {
                return null;
            }
            ByteArrayOutputStream baos = new ByteArrayOutputStream ();
            bm.compress (Bitmap.CompressFormat.PNG, 100, baos);
            return baos.toByteArray ();
        }

        /*
         * byte[] → Bitmap
         */
        private static Bitmap Bytes2Bimap (byte[] b) {
            if (b.length == 0) {
                return null;
            }
            return BitmapFactory.decodeByteArray (b, 0, b.length);
        }

        /*
         * Drawable → Bitmap
         */
        private static Bitmap drawable2Bitmap (Drawable drawable) {
            if (drawable == null) {
                return null;
            }
            // 取 drawable 的长宽
            int w = drawable.getIntrinsicWidth ();
            int h = drawable.getIntrinsicHeight ();
            // 取 drawable 的颜色格式
            Bitmap.Config config = drawable.getOpacity () != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565;
            // 建立对应 bitmap
            Bitmap bitmap = Bitmap.createBitmap (w, h, config);
            // 建立对应 bitmap 的画布
            Canvas canvas = new Canvas (bitmap);
            drawable.setBounds (0, 0, w, h);
            // 把 drawable 内容画到画布中
            drawable.draw (canvas);
            return bitmap;
        }

        /*
         * Bitmap → Drawable
         */
        @SuppressWarnings ("deprecation")
        private static Drawable bitmap2Drawable (Bitmap bm) {
            if (bm == null) {
                return null;
            }
            BitmapDrawable bd = new BitmapDrawable (bm);
            bd.setTargetDensity (bm.getDensity ());
            return new BitmapDrawable (bm);
        }
    }

    /**
     * Provides a means to save a cached file before the data are available.
     * Since writing about the file is complete, and its close method is called,
     * its contents will be registered in the cache. Example of use:
     *
     * ACache cache = new ACache(this) try { OutputStream stream =
     * cache.put("myFileName") stream.write("some bytes".getBytes()); // now
     * update cache! stream.close(); } catch(FileNotFoundException e){
     * e.printStackTrace() }
     */
    class xFileOutputStream extends FileOutputStream {
        File file;

        xFileOutputStream (File file) throws FileNotFoundException {
            super (file);
            this.file = file;
        }

        public void close () throws IOException {
            super.close ();
            mCache.put (file);
        }
    }

    /**
     * @author 杨福海（michael） www.yangfuhai.com
     * @version 1.0
     */
    public class ACacheManager {
        private final AtomicLong cacheSize;
        private final AtomicInteger cacheCount;
        private final long sizeLimit;
        private final int countLimit;
        private final Map<File, Long> lastUsageDates = Collections.synchronizedMap (new HashMap<File, Long> ());
        File cacheDir;

        private ACacheManager (File cacheDir, long sizeLimit, int countLimit) {
            this.cacheDir = cacheDir;
            this.sizeLimit = sizeLimit;
            this.countLimit = countLimit;
            cacheSize = new AtomicLong ();
            cacheCount = new AtomicInteger ();
            calculateCacheSizeAndCacheCount ();
        }

        /**
         * 计算 cacheSize和cacheCount
         */
        private void calculateCacheSizeAndCacheCount () {
            new Thread (new Runnable () {
                @Override
                public void run () {
                    int size = 0;
                    int count = 0;
                    File[] cachedFiles = cacheDir.listFiles ();
                    if (cachedFiles != null) {
                        for (File cachedFile : cachedFiles) {
                            size += calculateSize (cachedFile);
                            count += 1;
                            lastUsageDates.put (cachedFile, cachedFile.lastModified ());
                        }
                        cacheSize.set (size);
                        cacheCount.set (count);
                    }
                }
            }).start ();
        }

        private void put (File file) {
            int curCacheCount = cacheCount.get ();
            while (curCacheCount + 1 > countLimit) {
                long freedSize = removeNext ();
                cacheSize.addAndGet (-freedSize);

                curCacheCount = cacheCount.addAndGet (-1);
            }
            cacheCount.addAndGet (1);

            long valueSize = calculateSize (file);
            long curCacheSize = cacheSize.get ();
            while (curCacheSize + valueSize > sizeLimit) {
                long freedSize = removeNext ();
                curCacheSize = cacheSize.addAndGet (-freedSize);
            }
            cacheSize.addAndGet (valueSize);

            Long currentTime = System.currentTimeMillis ();
            file.setLastModified (currentTime);
            lastUsageDates.put (file, currentTime);
        }

        private File get (String key) {
            File file = newFile (key);
            Long currentTime = System.currentTimeMillis ();
            file.setLastModified (currentTime);
            lastUsageDates.put (file, currentTime);

            return file;
        }

        private File newFile (String key) {
            return new File (cacheDir, key.hashCode () + "");
        }

        private boolean remove (String key) {
            File image = get (key);
            return image.delete ();
        }

        private void clear () {
            lastUsageDates.clear ();
            cacheSize.set (0);
            File[] files = cacheDir.listFiles ();
            if (files != null) {
                for (File f : files) {
                    f.delete ();
                }
            }
        }

        /**
         * 移除旧的文件
         */
        private long removeNext () {
            if (lastUsageDates.isEmpty ()) {
                return 0;
            }

            Long oldestUsage = null;
            File mostLongUsedFile = null;
            Set<Entry<File, Long>> entries = lastUsageDates.entrySet ();
            synchronized (lastUsageDates) {
                for (Entry<File, Long> entry : entries) {
                    if (mostLongUsedFile == null) {
                        mostLongUsedFile = entry.getKey ();
                        oldestUsage = entry.getValue ();
                    } else {
                        Long lastValueUsage = entry.getValue ();
                        if (lastValueUsage < oldestUsage) {
                            oldestUsage = lastValueUsage;
                            mostLongUsedFile = entry.getKey ();
                        }
                    }
                }
            }

            long fileSize = calculateSize (mostLongUsedFile);
            if (mostLongUsedFile.delete ()) {
                lastUsageDates.remove (mostLongUsedFile);
            }
            return fileSize;
        }

        private long calculateSize (File file) {
            return file.length ();
        }
    }
}